Study, modeling and development of infrared detectors in the range 8-12µm based on antennas and nano diodes

Published : 1 January 2023

The thesis concerns the study, modeling and development of infrared detectors based on antennas and MIM (Metal-Insulator-Metal) nanodiodes in the range 8-12 µm. These devices will operate at room temperature and will be manufactured in the CEA-LETI clean room.

The student began his thesis work with a theoretical study of the behavior of dielectric and conductive materials at very high frequencies and a bibliographic study on MIM and MIIM components with the associated electrical conduction mechanisms. The dielectric of the MIM capacitor is an Al2O3 or HfO2 or a combination of both with thicknesses ranging from 0.5 nm to 5 nm. These materials are fabricated by atomic layer deposition (ALD) techniques at 250°C and 300°C, other dielectrics will be studied within the framework of the thesis.

An electrical characterization of existing MIM and MIIM devices, previously manufactured by CEA LETI will be performed by the student.

In order to enhance electrical performances, different metals that are used in the MIM or MIIM devices will be tested and selected by their work function. The student will study, characterize and model the different devices in order to determine the dominant electronic transport phenomena such as the tunneling effect with the extraction of the different physical parameters.

In a second step, the student will start electromagnetic simulations in order to design adapted antennas working in the wavelength range of 8-12µm, then he will propose the design of new test structures and arrays with antennas combined with MIM or MIIM diodes. These structures will then be fabricated by the CEA LETI and will be characterized by the student.

The aim of this thesis is to model and produce infrared detectors with antennas and MIM (or MIIM) nano diodes devices with very small dimensions of the order of 50 nm x 50 nm with cut-off frequencies beyond 30 THz. The different electromagnetic simulations coupled to the characteristics of the different materials will help us to obtain predictive design rules in the infrared range (8-12µm).

The results of this work open a path towards ambient infrared heat detection and imaging and heat harvesting.

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